what will brown sugar or molasses do to this?

just ordered my ingredients for my Russian Imperial Stout. I want a complex brew that will take my taste buds on a huge journey, so i'd like to add everything up to the kitchen sink....

in that vain, i'm wondering what a few things will add to my beer....recipe:

1.25# english brown malt
1# english chocolat malt
1.25# crystal 120L
0.75# belgian special B

5# extra light DME
5# extra pale LME

1 oz Warrior (16% AA) @ 60 min
1 oz Fuggle (4.75% AA) @ 30 min
1 oz Fuggle (4.75%) @ 5 min

WLP007 Dry English Ale yeast

*my thoughts and wants are to add vanilla beans at some point.
>>>question 1: better to add vanilla at 15 min mark of boil or to secondary???

**i'd like (i think) to add either brown sugar or molasses to last 15 min of boil.
>>>question 2: i'm unsure what the above will do to beer, could someone describe what taste i may get from either?

>>>question 3: is the addition of brown sugar/molasses overkill?????

this is gonna age until the holidays if that helps.

gator

I use brown sugar and molasses, and they can add a pungent, fruity sweetness to a beer that mellows over time. Considering you're already using Crystal 120 and Special B, I think the answer to question 3 would be "yes."

you can soak the vanilla beans in rum for a few days then toss them in the secondary good luck sounds delicious